Radio Link Monitoring for Link-Budget-Limited Devices

ABSTRACT

A link-budget-limited wireless communication device (UE) may implement improved radio link monitoring procedures for enhancing the link-budget of the UE. The UE may monitor the radio link and may determine whether the radio link can support a lowest acceptable link quality according to a hysteresis-based comparison that uses threshold values to determine error rates associated with a physical control channel. The UE may also identify itself to the network as a link-budget-limited device, and the network may enable special link-budget enhancing features for the UE, including boosting the power of the resource elements (REs) carrying physical channel signaling/data to the UE. The UE may detect the presence of power boost and may estimate/determine the power boost level. The UE may modify the threshold values based on the power boost detection and/or results of the power boost level estimation/determination, and may use the modified threshold values for determining radio link quality during radio link monitoring.

PRIORITY CLAIM

This application claims benefit of priority of U.S. Provisional PatentApplication Ser. No. 62/255,364 titled “Radio Link Monitoring forLink-budget-limited Devices”, filed on Nov. 13, 2015, which is herebyincorporated by reference as though fully and completely set forthherein.

FIELD OF THE INVENTION

The present application relates to wireless devices, and moreparticularly to an apparatus, system, and method for improved radio linkmonitoring for link-budget-limited devices.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage.Additionally, there exist numerous different wireless communicationtechnologies and standards. Some examples of wireless communicationtechnologies include GSM, UMTS (associated with, for example, WCDMA orTD-SCDMA air interfaces), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2CDMA2000 (e.g., 1×RTT, 1×EV-DO, HRPD, eHRPD), IEEE802.11 (WLAN orWi-Fi), IEEE 802.16 (WiMAX), Bluetooth, and others.

In wireless data communications, automatic repeat request (ARQ; alsoreferred to as automatic repeat query), is used as an error-controlmethod for data transmission that uses acknowledgements (messages sentby the receiver indicating that it has correctly received a data frameor packet) and timeouts (specified time periods allowed to elapse beforean acknowledgment is received) to achieve reliable data transmissions.If the sender does not receive an acknowledgment before the timeout, itusually re-transmits the frame/packet until the acknowledgment isreceived, or the number of re-transmissions has exceeded a predefinedlimit.

Hybrid automatic repeat request (HARD) is a combination of high-rateforward error-correcting coding and ARQ error-control. In standard ARQ,redundant bits are added to the data to be transmitted using anerror-detecting code such as a cyclic redundancy check (CRC), withreceivers detecting a corrupted message requesting a new message fromthe sender. In Hybrid ARQ, the original data is encoded with a FEC(forward error correction or forward error coding) code, and the paritybits are either immediately transmitted along with the message, or theyare transmitted only upon request by a receiver that has detected anerroneous message. The FEC code is typically used to correct an expectedsubset of all errors that may occur, while the ARQ provides a fallbackto correct errors that cannot be corrected through the use of only theredundancy included in the initial transmission. Therefore, hybrid ARQoffers better performance in poor signal conditions, but at the expenseof significantly lower throughput during good signal conditions. Asignal quality crossover point may be defined, below which simple HARQmay be preferred, and above which basic ARQ may be used.

Long Term Evolution (LTE) has become the technology of choice for themajority of wireless network operators worldwide, providing mobilebroadband data and high-speed Internet access to their subscriber base.LTE defines a number of downlink (DL) physical channels, categorized astransport or control channels, to carry information blocks received fromthe MAC and higher layers. LTE also defines various physical layerchannels for the uplink (UL).

The Physical Downlink Shared Channel (PDSCH) is a DL transport channel,and is the main data-bearing channel allocated to users on a dynamic andopportunistic basis. The PDSCH carries data in Transport Blocks (TB)corresponding to a media access control protocol data unit (MAC PDU),passed from the MAC layer to the physical (PHY) layer once perTransmission Time Interval (TTI). The PDSCH is also used to transmitbroadcast information such as System Information Blocks (SIB) and pagingmessages.

The Physical Downlink Control Channel (PDCCH) is a DL control channelthat carries the resource assignment for UEs that are contained in aDownlink Control Information or Indicator (DCI) message. Multiple PDCCHscan be transmitted in the same subframe using Control Channel Elements(CCE), each of which is a nine set of four resource elements known asResource Element Groups (REG). The PDCCH employs quadrature phase-shiftkeying (QPSK) modulation, with four QPSK symbols mapped to each REG.Furthermore, 1, 2, 4, or 8 CCEs can be used for a UE, depending onchannel conditions, to ensure sufficient robustness.

Wireless communication can be useful for a wide breadth of deviceclasses, ranging from relatively simple (e.g., potentially inexpensive)devices, which may have limited capabilities, to relatively complex(e.g., potentially more expensive) devices, which may have greatercapabilities. Such devices may have different characteristics withrespect to processing, memory, battery, antenna (power/range,directionality), and/or other capabilities. Devices that exhibitrelatively limited reception and/or transmission capabilities (due todevice design, device size, battery size, current transmission mediumconditions, and/or other factors) may be referred to in some instancesas “link-budget-limited” or “link-budget-limited” devices. It would bedesirable to provide improved packet switched wireless communicationservices to various types of mobile devices, includinglink-budget-limited devices.

Other corresponding issues related to the prior art will become apparentto one skilled in the art after comparing such prior art with thepresent invention as described herein.

SUMMARY OF THE INVENTION

In light of the foregoing and other concerns, some embodiments relate toa wireless communication device or user equipment (UE) configured toperform accurate radio link monitoring. In some embodiments, alink-budget-limited wireless communication device may implement improvedradio link monitoring procedures for enhancing the link-budget of theUE. The UE may monitor the radio link from the network, and maydetermine whether the radio link can support a lowest acceptable linkquality according to a hysteresis-based comparison that uses at leasttwo threshold values in determining block error rates associated with aphysical control channel, such as the Physical Downlink Control Channel(PDCCH). The UE may also identify itself to the network as belonging tospecial class of devices, more specifically a class that includeslink-budget-limited devices. Responsive to identifying the UE as alink-budget-limited device, the network may enable special link-budgetenhancing features for the UE.

The special link-budget enhancing features may include the network (orbase station facilitating communications of the UE according to thegiven radio access technology) boosting or increasing the power of theresource elements (REs) carrying physical channel signaling/data to theUE above what may be considered normal or customary power levels thenetwork uses for communicating with other (standard ornon-link-budget-limited) wireless communication devices. In other words,the network may increase the power at which the aforementioned resourceelements are transmitted with respect to the power levels otherwise usedby the network for transmission of those resource elements. Furthermore,the network may increase the power level at which those resourceelements are transmitted to be higher than the power levels at which thenetwork was transmitting those resource elements prior to the UEidentifying itself to the network as a link-budget-limited device. Inturn, the UE may detect the presence of a power boost (increase) and mayestimate/determine the power boost level, or the amount by which thepower used for transmitting the given resource elements was increased bythe network. The UE may modify the (at least two) threshold values basedon (or according to) the power boost detection and/or results of thepower boost level estimation/determination, and may use the modifiedthreshold values for determining radio link quality during radio linkmonitoring, to more accurately determine the radio link quality.

This Summary is intended to provide a brief overview of some of thesubject matter described in this document. Accordingly, it will beappreciated that the above-described features are merely examples andshould not be construed to narrow the scope or spirit of the subjectmatter described herein in any way. Other features, aspects, andadvantages of the subject matter described herein will become apparentfrom the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the embodiments is considered inconjunction with the following drawings.

FIG. 1 illustrates an exemplary (and simplified) wireless communicationsystem, according to some embodiments;

FIG. 2 illustrates an exemplary base station in communication with anexemplary wireless communication device (UE), according to someembodiments;

FIG. 3 illustrates an exemplary cellular network system according tosome embodiments;

FIG. 4 illustrates the block diagram of an exemplary UE, according tosome embodiments;

FIG. 5 illustrates the block diagram of an exemplary base station,according to some embodiments;

FIG. 6 is a flowchart diagram of an exemplary method for alink-budget-limited UE performing radio link monitoring, according to afirst set of embodiments;

FIG. 7 is a flowchart diagram of an exemplary method for alink-budget-limited UE performing radio link monitoring, according to asecond set of embodiments; and

FIG. 8 is a flowchart diagram of an exemplary method for alink-budget-limited UE performing radio link monitoring, according to athird set of embodiments.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and are herein described in detail. It should beunderstood, however, that the drawings and detailed description theretoare not intended to limit the invention to the particular formdisclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the present invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS Acronyms

Acronyms that may appear throughout the present Patent Application:

-   -   UE: User Equipment    -   BS: Base Station    -   ENB: eNodeB (Base Station)    -   GSM: Global System for Mobile Communication    -   UMTS: Universal Mobile Telecommunication System    -   LTE: Long Term Evolution    -   CS: Circuit-switched    -   PS: Packet-switched    -   CSFB: Circuit-switched fallback    -   MME: Mobile Management Entity    -   MSC: Mobile Switching Center    -   RNC: Radio Network Controller    -   RRC: Radio Resource Control    -   MT: Mobile Terminating    -   RLM: Radio Link Monitoring    -   RE: Resource Element[s]    -   BLER: Block Error Rate    -   PDCCH: Physical Downlink Control Channel    -   PDSCH: Physical Downlink Shared Channel    -   SNR: Signal-to-Noise Ratio    -   RLF: Radio Link Failure    -   CRS: Cell-Specific Reference Signals    -   RB: Resource Block    -   CQI: Channel Quality Indicator    -   SINR: Signal-To-Interference-Plus-Noise Ratio    -   DCI: Downlink Control Information    -   TTI: Transmit Time Interval    -   SIB: System Information Block

Terms

The following is a glossary of terms used in the present application:

Memory Medium—Any of various types of memory devices or storage devices.The term “memory medium” is intended to include an installation medium,e.g., a CD-ROM, floppy disks 104, or tape device; a computer systemmemory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM,Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media,e.g., a hard drive, or optical storage; registers, or other similartypes of memory elements, etc. The memory medium may comprise othertypes of memory as well or combinations thereof. In addition, the memorymedium may be located in a first computer in which the programs areexecuted, or may be located in a second different computer whichconnects to the first computer over a network, such as the Internet. Inthe latter instance, the second computer may provide programinstructions to the first computer for execution. The term “memorymedium” may include two or more memory mediums which may reside indifferent locations, e.g., in different computers that are connectedover a network.

Carrier Medium—a memory medium as described above, as well as a physicaltransmission medium, such as a bus, network, and/or other physicaltransmission medium that conveys signals such as electrical,electromagnetic, or digital signals.

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), television system, grid computing system, or otherdevice or combinations of devices. In general, the term “computersystem” can be broadly defined to encompass any device (or combinationof devices) having at least one processor that executes instructionsfrom a memory medium.

User Equipment (UE) (or “UE Device”)—any of various types of computersystems devices which are mobile or portable and which performs wirelesscommunications. Examples of UE devices include mobile telephones orsmart phones (e.g., iPhone™, Android™-based phones), portable gamingdevices (e.g., Nintendo DS™, Play Station Portable™, Gameboy Advance™,iPhone™), wearable electronic devices such as smart watches and/or smartglasses (e.g. Apple Watch™, Google Glass™), laptops, PDAs, portableInternet devices, music players, data storage devices, or other handhelddevices, etc. In general, the term “UE” or “UE device” can be broadlydefined to encompass any electronic, computing, and/ortelecommunications device (or combination of devices) which is easilytransported by a user and capable of wireless communication.

Processing Element—refers to various elements or combinations ofelements that are capable of performing a function in a device, e.g. ina user equipment device or in a cellular network device. Processingelements may include, for example: processors and associated memory,portions or circuits of individual processor cores, entire processorcores, processor arrays, circuits such as an ASIC (Application SpecificIntegrated Circuit), programmable hardware elements such as a fieldprogrammable gate array (FPGA), as well any of various combinations ofthe above.

Link-budget-limited—includes the full breadth of its ordinary meaning,and at least includes a characteristic of a wireless device (a UE) whichexhibits limited communication capabilities, or limited power, relativeto a device that is not link-budget-limited, or relative to devices forwhich a radio access technology (RAT) standard has been developed. A UEthat is link-budget-limited may experience relatively limited receptionand/or transmission capabilities, which may be due to one or morefactors such as device design, device size, battery size, antenna sizeor design, transmit power, receive power, current transmission mediumconditions, and/or other factors. Such devices may be referred to hereinas “link-budget-limited” (or “link-budget-constrained”) devices. Adevice may be inherently link-budget-limited due to its size, batterypower, and/or transmit/receive power. For example, a smart watch that iscommunicating over LTE or LTE-A with a base station may be inherentlylink-budget-limited due to its reduced transmit/receive power and/orreduced antenna. Wearable devices, such as smart watches, are generallylink-budget-limited devices. Alternatively, a device may not beinherently link-budget-limited, e.g., may have sufficient size, batterypower, and/or transmit/receive power for normal communications over LTEor LTE-A, but may be temporarily link-budget-limited due to currentcommunication conditions, e.g., a smart phone being at the edge of acell, etc. It is noted that the term “link-budget-limited” includes orencompasses power limitations, and thus a power limited device may beconsidered a link-budget-limited device.

Channel—a medium used to convey information from a sender (transmitter)to a receiver. It should be noted that since the definition of the term“channel” may differ according to different wireless protocols, the term“channel” as used herein should be considered as being used in a mannerthat is consistent with the standard of the type of device withreference to which the term is used. In some standards, channel widthsmay be variable (e.g., depending on device capability, band conditions,etc.). For example, LTE may support scalable channel bandwidths from 1.4MHz to 20 MHz. In contrast, WLAN channels may be 22 MHz wide whileBluetooth channels may be 1 Mhz wide. Other protocols and standards mayinclude different definitions of channels. Furthermore, some standardsmay define and use multiple types of channels, e.g., different channelsfor uplink or downlink and/or different channels for different uses suchas data, control information, etc.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thusthe term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually”, where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

DCI—refers to downlink control information. There are various DCIformats used in LTE in PDCCH (Physical Downlink Control Channel). TheDCI format is a predefined format in which the downlink controlinformation is packed/formed and transmitted in PDCCH.

FIGS. 1 and 2—Communication System

FIG. 1 illustrates a simplified exemplary wireless cellularcommunication system. It is noted that the system of FIG. 1 is merelyone example of a possible cellular communication system, and embodimentsof the invention may be implemented in any of various systems asdesired.

As shown, the example wireless cellular communication system includesbase stations 102A, 102B ... 102N, which, for the purposes ofdescription herein, may be collectively referred to as base station 102.Base station 102 communicates over a transmission medium with one ormore user devices 106A, 106B . . . 106N, which, for the purposes ofdescription herein, may be collectively referred to as UE 106. Each ofthe user devices may be referred to herein as a “user equipment” (UE).Thus, the user devices 106 are also referred to as UEs 106 or UE devices106.

The base station 102 may be a base transceiver station (BTS) or cellsite or an eNB, and may include hardware that enables wireless cellularcommunication with the UEs 106A-106N. The base station 102 may also beequipped to communicate with a network 100. Thus, the base station 102may facilitate communication between the UEs and/or between the UEs andthe network 100. The communication area (or coverage area) of each basestation may be referred to as a “cell.” Furthermore, network 100 may berepresentative of one or more base stations facilitating communicationsof UEs 106 according to a specific radio access technology (RAT) asdescribed above, with the base stations acting/operating as networkaccess points. As will be further described below, a network, e.g. acellular) network, may include additional access points beside the oneor more base stations. In general, base station 102 may be considered anetwork element responsible for radio transmission and reception in oneor more cells to or from UEs 106A-106N. Base station 102 may have anintegrated antenna or be connected to an antenna by feeder cables.Furthermore, a “cell” may be defined as a network object that may beuniquely identified by UE 106 from a (cell) identification that isbroadcast over a geographical area from a network access point. Thus, a“cell” may also be considered a logical identity for a given coveragearea at a given frequency. Base station 102 may serve any number ofcells, and cells served by base station 102 may or may not becollocated.

The base station 102 and the UEs 106 may be configured to communicateover the

transmission medium using any of various wireless communicationtechnologies or RATs, including cellular RATs such as GSM, UMTS, LTE,LTE-Advanced, CDMA, W-CDMA, and any of various 3G, 4G, 5G or futuretelecom standards. Base station 102 and other similar base stationsoperating according to the same or a different cellular communicationstandard may thus be provided as a network of cells, which may providecontinuous or nearly continuous overlapping service to UE 106 andsimilar devices over a wide geographic area via one or more cellularcommunication standards. Other possible wireless communicationtechnologies include wireless local area network (WLAN or WiFi), WiMAX,etc.

In some embodiments, UE 106 may be capable of communicating usingmultiple radio RATs. For example, the UE 106 might be configured tocommunicate using two or more of GSM, UMTS, LTE, LTE-Advanced CDMA2000,WLAN, Bluetooth, one or more global navigational satellite systems(GNSS, e.g., GPS or GLONASS), one and/or more mobile televisionbroadcasting standards (e.g., ATSC-M/H or DVB-H), etc. Othercombinations of wireless communication standards (including more thantwo wireless communication standards) are also possible.

FIG. 2 illustrates an exemplary UE 106 (e.g., one of the UEs 106A-106N)in communication with an exemplary base station 102, according to someembodiments. As defined above, the UE 106 may be a device with wirelesscellular network connectivity such as a mobile phone, a hand-helddevice, a computer or a tablet, or virtually any type of wirelessdevice. The base station may be a cellular base station thatcommunicates in a wireless cellular manner with one or more UEs.

The UE may include a processing element such as one or more of aprocessor, an ASIC (application specific integrated circuit), an FPGA(field-programmable gate array) or some combination thereof. The UE,such as the processing element in the UE, may perform any of the methodsdescribed herein as being performed by a UE.

The base station may include a processing element such as one or more ofa processor, an ASIC (application specific integrated circuit), an FPGA(field-programmable gate array) or some combination thereof. The basestation, such as the processing element in the base station, may performany of the methods described herein as being performed by a basestation. Other cellular network devices, described below, may also beconfigured to perform some or all of the methods described herein,possibly in conjunction with the base station.

In some embodiments, the UE 106 may be configured to communicate usingany of multiple wireless communication protocols as described above. TheUE 106 may include one or more antennas for communicating using one ormore wireless communication protocols. In some embodiments, the UE 106may share one or more parts of a receive and/or transmit chain betweenmultiple wireless communication standards. The shared radio may includea single antenna, or may include multiple antennas (e.g., for MIMO) forperforming wireless communications. In other embodiments, the UE 106 mayinclude separate transmit and/or receive chains (e.g., includingseparate antennas and other radio components) for each wirelesscommunication protocol with which it is configured to communicate. Instill other embodiments, the UE 106 may include one or more radios whichare shared between multiple wireless communication protocols, and one ormore radios which are used exclusively by a single wirelesscommunication protocol. For example, in one set of embodiments, the UE106 may include a shared radio for communicating using either of LTE or1×RTT, and separate radios for communicating using each of Wi-Fi andBluetooth. Other configurations are also possible.

The UE may be associated with, e.g., subscribe to, a cellular carrier.Examples of cellular carries in the United States include Verizon, AT&T,Sprint, and T-Mobile.

FIG. 3 illustrates a simplified portion of an exemplary wirelesscommunication system that may be used in some embodiments. As shown inFIG. 3, the UE 106 may be in communication with a cellular network,where the cellular network may include a base station 102 and an evolvedpacket core (EPC) 101, as shown, among other possible elements. The basestation is shown in this example embodiment as an eNodeB 102. The UE 106may communicate in a wireless manner with the base station (eNodeB) 102.In turn, the eNodeB 102 may be coupled to a core network, shown in thisexample embodiment as an evolved packet core (EPC) 101. As shown, theEPC 101 may include mobility management entity (MME) 322, homesubscriber server (HSS) 324, and serving gateway (SGW) 326. The EPC 100may include various other devices known to those skilled in the art aswell.

Operations described herein as being performed by the cellular network(or simply referred to as “the network”) may be performed by one or moreof the cellular network devices shown in FIG. 3, such as one or more ofbase station, 102, MME 322, HSS 324, or SGW 326 in EPC 100, amongpossible others.

FIG. 4—Example Block Diagram of a UE

FIG. 4 illustrates a block diagram of an exemplary UE 106, according tosome embodiments. As shown, the UE 106 may include a system on chip(SOC) 400, which may include portions for various purposes. For example,as shown, the SOC 400 may include a processing element, such asprocessor(s) 402 which may execute program instructions for the UE 106and display circuitry 404 which may perform graphics processing andprovide display signals to the display 440. The processor(s) 402 mayalso be coupled to memory management unit (MMU) 440, which may beconfigured to receive addresses from the processor(s) 402 and translatethose addresses to locations in memory (e.g., memory 406, read onlymemory (ROM) 450, NAND flash memory 410) and/or to other circuits ordevices, such as the display circuitry 404, radio 430, connector I/F420, and/or display 440. The MMU 440 may be configured to perform memoryprotection and page table translation or set up. In some embodiments,the MMU 440 may be included as a portion of the processor(s) 402.

In the embodiment shown, ROM 450 may include a bootloader, which may beexecuted by the processor(s) 402 during boot up or initialization. Asalso shown, the SOC 400 may be coupled to various other circuits of theUE 106. For example, the UE 106 may include various types of memory(e.g., including Flash memory 410), a connector interface 420 (e.g., forcoupling to the computer system), the display 440, and wirelesscommunication circuitry (e.g., for LTE, LTE-A, CDMA2000, GSM,BLUETOOTHTM, Wi-Fi, etc.).

The UE device 106 may include at least one antenna, and in someembodiments multiple antennas, for performing wireless cellularcommunication with base stations and/or wireless communication withother devices. For example, the UE device 106 may use antenna 435 toperform the wireless cellular communication and may use antenna 436 forother wireless communication. As noted above, the UE may be configuredto communicate wirelessly using multiple wireless communicationstandards (multiple RATs) in some embodiments. In some embodiments UE106 may be designed to use both antennas 435 and 436 to perform wirelesscellular communications.

As described herein, the UE 106 may include a processing element, e.g.,hardware and/or software components for implementing methods accordingto embodiments of this disclosure.

The processing element of the UE device 106 may be processor 402configured to implement part or all of the methods described herein,e.g., by executing program instructions stored on a memory medium (e.g.,a non-transitory computer-readable memory medium). In other embodiments,the UE processing element may be configured as a programmable hardwareelement, such as an FPGA (Field Programmable Gate Array), or as an ASIC(Application Specific Integrated Circuit).

FIG. 5—Base Station

FIG. 5 illustrates a block diagram of an exemplary base station 102,according to some embodiments. It is noted that the base station of FIG.5 is merely one example of a possible base station. As shown, the basestation 102 may include a processing element, such as processor(s) 504which may execute program instructions for the base station 102. Theprocessor(s) 504 may also be coupled to memory management unit (MMU)540, which may be configured to receive addresses from the processor(s)504 and translate those addresses to locations in memory (e.g., memory560 and read only memory (ROM) 550) or to other circuits or devices.

The base station 102 may include at least one network port 570. Thenetwork port 570 may be configured to couple to a telephone network andprovide a plurality of devices, such as UE devices 106, access to thetelephone network as described above.

The network port 570 (or an additional network port) may also oralternatively be configured to couple to a cellular network, e.g., acore network of a cellular service provider. The core network mayprovide mobility related services and/or other services to a pluralityof devices, such as UE devices 106. In some cases, the network port 570may couple to a telephone network via the core network, and/or the corenetwork may provide a telephone network (e.g., among other UE devices106 serviced by the cellular service provider).

The base station 102 may include at least one antenna 534. The at leastone antenna 534 may be configured to operate as a wireless transceiverand may be further configured to communicate with UE devices 106 viaradio 530. The antenna 534 communicates with the radio 530 viacommunication chain 532. Communication chain 532 may be a receive chain,a transmit chain or both. The radio 530 may be configured to communicatevia various RATs, including, but not limited to, GSM, UMTS, LTE, LTE-A,WCDMA, CDMA2000, etc.

The processing element, such as processor(s) 504, of the base station102 may be configured to implement part or all of the methods describedherein, e.g., by executing program instructions stored on a memorymedium (e.g., a non-transitory computer-readable memory medium).Alternatively, the processing element may be configured as aprogrammable hardware element, such as an FPGA (Field Programmable GateArray), or as an ASIC (Application Specific Integrated Circuit), or acombination thereof.

Radio Link Monitoring

In general, the design and development of cellular networks wasperformed under the assumption that devices have regular link budgetcharacteristics, e.g., for devices such as smart phones, tablets, etc.“Regular”, in this context, may simply refer to an expected powerspectrum or power range typically associated with wireless transmissionsof control signaling and data to and/or from the devices. E.g., variouswireless communication device may be expected to require a certain power(or power within a certain range) for transmission of control signalingand data to and/or from the devices. However, with the introduction of anew class of devices, in particular wearable devices such as smartwatches, which are link-budget-limited, certain network parameters mayresult in sub-optimal operation for the link-budget-limited devices.

For example, a UE device that is 3GPP compliant may be configured tomonitor the radio link from the base station (eNodeB) and make adetermination whether the radio link has failed in terms of not havingthe capability or capacity to support the lowest acceptable linkquality. For example, the UE may monitor the quality of the radio linkbetween the bases station and the UE, to determine whether that radiolink quality is supports communications between the UE and the basestation. The radio link monitoring (RLM) procedure currently specifiedby 3GPP (e.g. in section 7.6 of 3GPP TS 36.133) is a hysteresis-basedthreshold comparison of the serving cell channel quality with twothresholds called “Qin” and “Qout”. That is, the RLM procedure mayinclude a hysteresis-based comparison that uses two threshold values,where the first threshold value (“out of sync” threshold Qout) isdefined as the level at or above which the Physical Downlink ControlChannel (PDCCH) block error rate (BLER) is higher than a specified firstpercentage (e.g. 10%) for the UE. The second threshold value (“in sync”threshold Qin) is defined as the level at or below which the PDCCH BLERis lower than a specified second percentage (e.g. case 2%) for the UE.With respect to LTE, the format of the Downlink Control Information(DCI) for this hypothetical PDCCH is specified by the 3GPPspecification[s].

The UE typically bases its estimate of the PDCCH BLER on its downlink(DL) Signal-to-Noise Ratio (SNR) computation using cell-specificreference signals (CRS) and its mapping to a channel quality metricassociated with a certain target BLER. The BLER estimate is filtered byhigher UE layers, which provide a radio link failure (RLF) decisionbased on the filtered BLER estimates. The UE may determine the radiolink quality in every DL subframe in which it is awake (as specified in3GPP TS 36.213, section 4.2.1). However the base station (eNodeB) mayrestrict the subframes over which RLM is conducted/performed (e.g. asspecified in 3GPP TS 36.331).

Radio Link Monitoring by Link-Budget-Limited Devices

In some embodiments, devices considered to be link-budget-limited UEs(e.g. wireless communication devices that belong to a class designatedto include or correspond to link-budget-limited devices) may identifythemselves to the network as being such a device, based on anagreed-upon protocol which may fall outside the scope of current 3GPPspecifications. In response to being informed by the device that thedevice is a link-budget-limited device, (or is a class of device thatincludes link-budget-limited devices) the network may enable speciallink budget enhancing features for this class of UEs. One such featuremay be the network (e.g., the base station or eNB, in some embodiments)boosting the power of the resource elements (RE) carrying PDCCH andPDSCH for the UE. That is, the cellular network (or base station) mayoperate to boost, or increase the power used for (or associated with)transmission of the resource elements carrying signal[s] and dataassociated with the physical channels for the UE. For example, thenetwork may use higher power level(s) to transmit those resourceelements carrying the signal[s] and data associated with the physicalchannels for the UE than the power level(s) at which the network wouldbe transmitting those resource elements under normal operatingconditions. The higher power level(s) may also represent an increasewith respect to the power level(s) used by the network for (or the powerassociated with) transmitting the same resource elements to all otherdevices with which the base station (or the cellular network) conductswireless communications. However, the power level(s) for transmittingCRS may not be boosted because CRS are not UE specific, that is, theyare not specific to the UE, and therefore affect communications of thebase station or network with other wireless communication devices aswell. The power boosting may be enabled at the discretion of thecellular network when the cellular network determines that the UE is ina coverage scenario where the UE may not be able to otherwise sustainthe link. For example, the network may determine whether a power boostis required in order for the UE to be able to sustain the radio link tothe network, and the network may boost or not boost the poweraccordingly.

In some embodiments, the power level(s) of REs carrying CRS relative tothe power level(s) of REs carrying data may be determined according toone or more network configured parameters. Specifically in the case ofLTE, these parameters are the pA and pB parameters per 3GPPspecifications. The power boost, when applied, may result in powerlevel(s) that are above the values or above power level(s) determinedbased on these parameters. The boosting of PDCCH power (or the powerlevel(s) used for transmitting the PDCCH) improves the achievable BLERon the PDCCH for the UE. But since the RLM computation is based on theprediction of hypothetical PDCCH BLER based on CRS, it predicts the sameBLER regardless of whether the power boost is enabled or not. Therefore,at the UE, there is a need to detect the presence of power boost andadjust the RLM thresholds in the presence of power boost to reflect theimprovement in the BLER due to the power boost.

Improved Radio Link Monitoring

In at least some embodiments described herein, a link-budget-limitedwireless communication device may implement improved radio linkmonitoring procedures for enhancing the link-budget of the wirelesscommunication device, or, in other words, for reducing any link-budgetlimiting the wireless communication device may be subject to. Aspreviously mentioned, the wireless communication device may belong to aspecified class of link-budget-limited wireless communication devices(or link-budget-limited UEs), which may identify themselves—based on anagreed upon protocol with the network, for example—to the network (orcell, or base station) as being a link-budget-limited device. Thenetwork may then enable special link-budget enhancing features for theUE, including boosting the power of the resource elements (RE) carryingPDCCH and PDSCH signaling and/or data (physical channel signaling/data)for the UE. The network may boost the power used for transmitting theREs carrying the above referenced signaling and/or data by a specifiedamount, for example by selecting a boost value from a specified(discrete) set of values, such as 1 dB to 6 dB in some embodiments. TheUE may then detect the presence of such power boost on REs carrying datafor the UE, e.g. on PDCCH and PDSCH. In some embodiments, the powerboost may be detected and/or identified for each transmit time interval(TTI). That is, the UE may perform a power boost detection at each TTI.

Detecting Power Boost According to Some Embodiments

In some embodiments, the UE may determine the relative power level ofcell-specific reference signals (CRS) and data-carrying REs based on aspecified set of one or more network parameters. For example, the UE mayuse one or more specified parameters corresponding to the RAT network onwhich the UE is communicating, to determine the relative power level ofreference signals corresponding to the given network and also todetermine the power level of REs carrying data during the wirelesscommunications over the given network. For example, when the givennetwork is a 3GPP network (e.g. LTE network), the first networkparameter may be pA (indicative of the ratio of the data subcarrierpower of OFDM symbols excluding pilot symbols to the pilot subcarrierpower) and the second network parameter may be pB (indicative of theratio of the data subcarrier power of OFDM symbols including pilotsymbols to the pilot subcarrier power), as described for example insection 5.2 of the 3GPP TS 36.213 specification. Network parameter pB(more specifically, the value of network parameter pB) is broadcast insystem information block 2 (SIB2), while network parameter pA (morespecifically, the value of network parameter pA) is included in radioresource control (RRC) connection setup message[s].

For a first physical channel, for example the Physical Downlink SharedChannel (PDSCH), the UE may measure a first power value, which may bethe average power of the REs carrying the reference signal[s]corresponding to the given network (e.g. the average power used fortransmitting the REs carrying CRS) in resource blocks (RBs) allocatedfor data transmitted to the UE. Similarly, the UE may measure a secondset of power values representative of the average power of data-carryingREs in the above referenced RBs for symbols that have reference signalREs. The second set of power values may be further representative of theaverage power of data-carrying REs in the above referenced RBs onsymbols that do not have reference signal REs. Subsequently, the UE mayadjust—based on pA and pB—the second power values for the relative powerdifference to determine the average power of a data-carrying RE. Thisadjusted power value is referred to as the adjusted second power value.The UE may then compare the adjusted second power value (average powerof a data-carrying RE) with the first power value (average power of areference signal carrying RE). If the ratio of the adjusted second powervalue (ASPV) to the first power value (FPV) is greater than a specifiedthreshold, e.g. if ASPV/FPV is greater than a specified value, then theUE may assume the presence of power boost on the first physical channel(e.g. on the PDSCH).

For a second physical channel, e.g. the Physical Downlink ControlChannel (PDCCH), the UE may measure a third power value, which may bethe average power of the REs carrying the reference signal[s]corresponding to the given network (i.e. the average power of the REscarrying CRS) allocated for the symbols associated with the secondphysical channel (e.g. the control channel). For an assumed aggregationlevel and location in user-specific search space, the UE may measure afourth set of power values, which may be representative of the averagepower of the REs carrying the information/data for the second physicalchannel (e.g. the average power of the REs carrying the PDCCH) insymbols that do not contain reference signal carrying REs. The fourthset of power values may also be representative of the average power ofthe REs carrying the information/data for the second physical channel(e.g. the average power of the REs carrying the PDCCH) in symbols thatcontain REs that carry reference signals. The UE may follow a proceduresimilar to the procedure described above with respect to the firstphysical channel (PDSCH). That is, the UE may adjust the fourth set ofpower values for the relative power difference based on pA to computethe average power of an information/data RE and compare the adjustedfourth power value with the third power value. This set of adjustedpower values is referred to as the adjusted fourth power value oradjusted fourth set of power values. If the ratio of adjusted fourthpower value (AFPV) to the third power value (TPV) is greater than aspecified threshold, e.g. if AFPV/TPV is greater than a specified value,then the UE may assume the presence of power boost on the secondphysical channel (e.g. on the PDCCH).

It should also be noted that by comparing the ratio of data RE power toCRS RE power, the UE may also estimate the amount (or degree, orpercentage, or level) of the power boost. For example, as mentionedabove, in some embodiments the network may boost the power by aspecified amount, for example by selecting a boost value from aspecified (discrete) set of values, such as 1 dB to 6 dB. By comparingthe ratio of data RE power to CRS RE power, the UE may estimate whichpower boost value was used by the network when boosting the power.

Detecting Power Boost According to Additional Embodiments

In some embodiments, the UE may report channel quality indicators (CQIs)or CQI values to the network (e.g. to the base station or eNodeB) as setforth according to the communication protocols of the RAT used for thewireless communications (e.g. according to LTE specifications during LTEcommunications). When the UE reports a CQI value that is within aspecified range of values, for example if the CQI value is zero or one,the UE may assume that the base station (or the network) will boost thepower for the first physical channel and the second physical channel(e.g. for PDSCH and PDCCH) for the UE in order to improve thelink-budget for the UE. At this point, the UE may start using modifiedthresholds for the RLM procedure until the CQI improves.

Alternatively (or in addition), in some embodiments, when the UEreceives PDSCH data/signaling with a modulation and coding scheme index(I_MCS) value that is within a specified range indicative of a transportblock size that is easiest to decode, e.g. I_MCS=0, the UE may assumethat the network has begun boosting the power for the first physicalchannel and the second physical channel (e.g. PDSCH and PDCCH) for theUE, and may use modified thresholds for the RLM procedure accordingly.When performing the alternate methods of detecting power boost, the UEmay be operating under the presumption that the power boost is the samefor both physical channels, and that the power boost level does notchange from transmit time interval to transmit time interval.

Use of Modified Thresholds

According to at least the power boost detection described above, the UEmay use modified RLM thresholds in the RLM procedure if the UE hasdetermined that the REs carrying data/signaling for the physicalchannels (e.g. PDCCH and PDSCH) intended for (or targeting) the UE havebeen power boosted by the network. At least in some embodiments, asdescribed above, detecting power boost allows the UE to determine theamount or level of boost applied by the network, which may allow the UEto also select the modified RLM threshold[s]. For example, similar tohow the network may boost the power according to values selected from aset (such as 1 dB to 6 dB, e.g.), the UE may also select the modifiedRLM threshold(s) from a set of values which may correspond to thevalues/levels by which the network has boosted the power. Accordingly,the network may use a set of boost values, while the UE may use a set ofRLM threshold values that corresponds to the set of boost values used bythe network (e.g. by an eNB).

The alternate methods of detecting the power boost as described abovemay be considered more limited, generally allowing for thedetermination/detection of the presence or absence of power boost,without precisely determining the possible value of the power boost. Insuch cases, in some embodiments, the UE may consider the power boostvalue to be a specified or set value, such as a specified maximum value(e.g., 6 dB in the power boost value range/set example provided above),and may adjust the RLM threshold (value) based on that specified powerboost value. Alternatively, the UE may compare the measured downlinkblock error rate (DL BLER) value—measured, for example, on the firstHARQ transmission—with a BLER value corresponding to the particularSignal-To-Interference-Plus-Noise Ratio (SINR) if there were no powerboosting by the network. The UE may store a lookup table that maps theeffective DL SINR (similar to the measurements of CQI) to the BLERvalue, and may determine the actual power boost value by measuring theactual DL BLER. The UE may perform the power boost valueestimation/determination according to the actual DL BLER with theassumption that the power boost for both physical channels (e.g. PDCCHand PDSCH) is the same. In some embodiments, the UE may adjust thethreshold in a closed-loop manner until the measured BLER valueconverges towards the corresponding BLER value derived from (or storedin) the lookup table. For example, the UE may keep adjusting thethreshold or threshold value until the measured BLER value and the BLERvalue stored in the lookup table (and based on the SINR) are equal toeach other or do not differ from each other by more than a specifieddifference value.

FIG. 6

FIG. 6 is a flowchart diagram of an exemplary method for alink-budget-limited UE performing radio link monitoring, according to afirst set of embodiments. As shown in FIG. 6, the UE may determinerelative power levels of first REs and second REs, with the first REscarrying reference signals specific to the cellular network and receivedby the UE, and the second REs carrying—to the UE over the cellularnetwork—signal[s] and/or data associated with physical channels (602).The UE may determine whether the cellular network has boosted, orincreased power of the second REs, based at least on the determinedrelative power levels (604), and may adjust radio link monitoring of theUE according to at least the determination of whether the cellularnetwork has boosted the power of the second REs (606).

In determining the relative power levels of the first and second REs,the UE may measure a first power value representative of an averagepower of the first REs, and a second power value representative of anaverage power of the second REs. The UE may also receive specifiednetwork parameters associated with the cellular network (e.g. the UE mayreceive values of the specified network parameters) from the cellularnetwork, and may determine the relative power levels of the REsaccording to at least the first power value, second power value, and therespective values of the specified network parameters (620). The UE mayadjust the radio link monitoring by adjusting respective values ofspecified threshold(s) used in determining whether the radio link is ofacceptable quality (630). The UE may also determine the power boostlevel by which the cellular network has boosted or increased the powerof the second REs (606), and may adjust the threshold(s) by selectingthreshold value(s) according to the determined power boost level,selecting the threshold value(s) from a set of specified thresholdvalues corresponding to a set of power boost values (640). Again, the“power level of an RE” is in reference to the power level(s) at whichthe REs are transmitted.

FIG. 7

FIG. 7 is a flowchart diagram of an exemplary method for alink-budget-limited UE performing radio link monitoring, according to asecond set of embodiments. As shown in FIG. 7, the UE may report channelquality indicator (CQI) value[s] to a cellular network (702), andresponsive to reporting a CQI value that is within a specified range ofCQI values, the UE may adjust radio link monitoring of the UE (704). TheUE may adjust the radio link monitoring based on a presumption that thecellular network has boosted, in response to the cellular networkreceiving the CQI value that is within the specified range of CQIvalues, a power of REs carrying—to the UE over the cellularnetwork—signal [s] and data associated with physical channels (704).

FIG. 8

FIG. 8 is a flowchart diagram of an exemplary method for alink-budget-limited UE performing radio link monitoring, according to athird set of embodiments. As shown in FIG. 8, the UE may receivephysical channel signaling with a modulation and coding scheme indexvalue that is within a specified range of modulation and coding schemeindex values (802). Responsive to receiving the modulation and codingscheme index value that is within the specified range, the UE may adjustradio link monitoring of the UE (804). The UE may adjust the radio linkmonitoring based on a presumption that the cellular network has boostedor increased, responsive to the cellular network sending the modulationand coding scheme index value that is within the specified range, apower of resource elements carrying—to the UE over the cellularnetwork—signal[s] and data associated with physical channels (804).

Various Embodiments

Pursuant to the above, in some embodiments, a UE may include at leastone antenna, a radio coupled to the antenna for performing wirelesscellular communications with a cellular network, and at least oneprocessing element coupled to the radio. The UE may report channelquality indicator (CQI) value[s] to the cellular network. In response toreporting a CQI value that is within a specified range of CQI values,the UE may adjust its radio link monitoring. The UE may adjust its radiolink monitoring based on a presumption that the cellular network hasboosted the power of resource elements carrying signal[s] and dataassociated with physical channels to the UE over the cellular network,in response to receiving the CQI value (from the UE) that is within thespecified range of CQI values.

In some embodiments, a UE may receive, from the cellular network,physical channel signaling with a modulation and coding scheme indexvalue that is within a specified range of modulation and coding schemeindex values. In response to receiving the modulation and coding schemeindex value that is within the specified range, the UE may adjust itsradio link monitoring. The UE may adjust its radio link monitoring (inresponse to the receiving the modulation and coding scheme index valuethat is within the specified range) based on a presumption that thecellular network has boosted, responsive to sending the modulation andcoding scheme index value that is within the specified range, a power ofresource elements carrying signal[s] and data associated with physicalchannels to the UE over the cellular network. The UE may also measure anerror rate of a downlink hybrid automatic repeat request transmission,estimate an actual error rate on a physical downlink shared channelbased on the measured error rate, perform a comparison of the estimatedactual error rate with an error rate predicted based on an SINR onreference symbols, and estimate, based on the comparison, an amount ofpower boost being used/applied by the cellular network.

Embodiments of the present disclosure may be realized in any of variousforms. For example, in some embodiments, the present invention may berealized as a computer-implemented method, a computer-readable memorymedium, or a computer system. In other embodiments, the presentinvention may be realized using one or more custom-designed hardwaredevices such as ASICs. In other embodiments, the present invention maybe realized using one or more programmable hardware elements such asFPGAs.

In some embodiments, a non-transitory computer-readable memory mediummay be configured so that it stores program instructions and/or data,where the program instructions, if executed by a computer system, causethe computer system to perform a method, e.g., any of a methodembodiments described herein, or, any combination of the methodembodiments described herein, or, any subset of any of the methodembodiments described herein, or, any combination of such subsets.

In some embodiments, a device (e.g., a UE) may be configured to includea processor (or a set of processors) and a memory medium, where thememory medium stores program instructions, where the processor isconfigured to read and execute the program instructions from the memorymedium, where the program instructions are executable to implement anyof the various method embodiments described herein (or, any combinationof the method embodiments described herein, or, any subset of any of themethod embodiments described herein, or, any combination of suchsubsets). The device may be realized in any of various forms.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

We claim:
 1. An apparatus for facilitating radio link monitoring, theapparatus comprising: a processing element configured to cause awireless communication device to: conduct wireless cellularcommunications with a cellular network; perform radio link monitoring;determine relative power levels of: first resource elements carryingreference signals specific to the cellular network; and second resourceelements carrying signals and data associated with one or more physicalchannels; determine whether the cellular network has boosted power ofthe second resource elements, based at least on the determined relativepower levels; and adjust the radio link monitoring according to at leastthe determination of whether the cellular network has boosted the powerof the second resource elements.
 2. The apparatus of claim 1, whereinthe processing element is configured to further cause the wirelesscommunication device to: determine the relative power levels of theresource elements according to respective values of specified networkparameters associated with the cellular network.
 3. The apparatus ofclaim 2, wherein the processing element is configured to further causethe wireless communication device to: receive the specified networkparameters from the cellular network.
 4. The apparatus of claim 1,wherein the processing element is configured to further cause thewireless communication device to: adjust the radio link monitoring byadjusting respective values of specified thresholds used in determiningwhether the radio link is of acceptable quality.
 5. The apparatus ofclaim 4, wherein the processing element is configured to further causethe wireless communication device to: determine a power boost level bywhich the cellular network has boosted the power of the second resourceelements if it is determined that the cellular network has boosted thepower of the second resource elements; and adjust the respective valuesof the specified thresholds by selecting threshold values, according tothe determined power boost level, from a set of specified thresholdvalues corresponding to a set of power boost values.
 6. The apparatus ofclaim 1, wherein the processing element is configured to further causethe wireless communication device to: determine the relative powerlevels by measuring: a first power value representative of an averagepower of the first resource elements; and a second power valuerepresentative of an average power of the second resource elements. 7.The apparatus of claim 1, wherein the processing element is configuredto further cause the wireless communication device to: report one ormore channel quality indicator (CQI) values to the cellular network; andin response to reporting a CQI value that is within a specified range ofCQI values, adjust radio link monitoring of the wireless communicationdevice.
 8. The apparatus of claim 1, wherein the processing element isconfigured to further cause the wireless communication device to:receive, from the cellular network, a physical channel signaling with amodulation and coding scheme index value that is within a specifiedrange of modulation and coding scheme index values; and in response toreceiving the modulation and coding scheme index value that is withinthe specified range, adjust radio link monitoring of the wirelesscommunication device.
 9. A wireless communication device comprising:radio circuitry comprising one or more antennas and configured tofacilitate wireless communications of the wireless communication deviceover a cellular network; and processing circuitry coupled to the radiocircuitry and configured to interoperate with the radio circuitry tocause the wireless communication device to: perform radio linkmonitoring; determine relative power levels of: first resource elementscarrying reference signals specific to the cellular network; and secondresource elements carrying signals and data associated with one or morephysical channels; determine, based at least on the determined relativepower levels, whether the cellular network has increased power at whichthe second resource elements are transmitted; and adjust the radio linkmonitoring according to at least the determination of whether thecellular network has increased the power at which the second resourceelements are transmitted.
 10. The wireless communication device of claim9, wherein the processing element is configured to interoperate with theradio circuitry to further cause the wireless communication device to:receive, from the cellular network, specified network parametersassociated with the cellular network; and determine the relative powerlevels of the resource elements according to respective values of thespecified network parameters received from the cellular network.
 11. Thewireless communication device of claim 9, wherein the processing elementis configured to interoperate with the radio circuitry to further causethe wireless communication device to: adjust the radio link monitoringby adjusting respective values of specified thresholds used indetermining whether the radio link is of acceptable quality.
 12. Thewireless communication device of claim 11, wherein the processingelement is configured to interoperate with the radio circuitry tofurther cause the wireless communication device to: determine a powerboost level by which the cellular network has increased the power atwhich the second resource elements are transmitted if it is determinedthat the cellular network has increased the power at which the secondresource elements are transmitted; and adjust the respective values ofthe specified thresholds by selecting threshold values, according to thedetermined power boost level, from a set of specified threshold valuescorresponding to a set of power boost values.
 13. The wirelesscommunication device of claim 11, wherein the processing element isconfigured to interoperate with the radio circuitry to further cause thewireless communication device to: compare a measured block error rate(BLER) value with a stored BLER value that corresponds to a previouslydetermined signal-to-noise-interference-ratio; and adjust the respectivevalues of the specified thresholds until the measured BLER value and thestored BLER value do not differ by more than a specified differencevalue.
 14. A non-transitory memory medium storing instructionsexecutable by a processing element to cause a wireless communicationdevice to: perform radio link monitoring; determine relative powerlevels of: first resource elements carrying reference signals specificto the cellular network; and second resource elements carrying signalsand data associated with one or more physical channels; determine, basedat least on the determined relative power levels, whether the cellularnetwork has increased power at which the second resource elements aretransmitted; and adjust the radio link monitoring according to at leastthe determination of whether the cellular network has increased thepower at which the second resource elements are transmitted.
 15. Thenon-transitory memory medium of claim 14, wherein the instructions areexecutable by the processing element to further cause the wirelesscommunication device to: receive, from the cellular network, specifiednetwork parameters associated with the cellular network; and determinethe relative power levels of the resource elements according torespective values of the specified network parameters received from thecellular network.
 16. The non-transitory memory medium of claim 14,wherein the instructions are executable by the processing element tofurther cause the wireless communication device to: adjust the radiolink monitoring by adjusting respective values of specified thresholdsused in determining whether the radio link is of acceptable quality. 17.The non-transitory memory medium of claim 16, wherein the instructionsare executable by the processing element to further cause the wirelesscommunication device to: determine a power boost level by which thecellular network has increased the power at which the second resourceelements are transmitted if it is determined that the cellular networkhas increased the power at which the second resource elements aretransmitted; and adjust the respective values of the specifiedthresholds by selecting threshold values, according to the determinedpower boost level, from a set of specified threshold valuescorresponding to a set of power boost values.
 18. The non-transitorymemory medium of claim 14, wherein the instructions are executable bythe processing element to further cause the wireless communicationdevice to determine the relative power levels by measuring: a firstpower level representative of an average power at which the firstresource elements are transmitted; and a second power levelrepresentative of an average power at which the second resource elementsare transmitted.
 19. The non-transitory memory medium of claim 14,wherein the instructions are executable by the processing element tofurther cause the wireless communication device to: report one or morechannel quality indicator (CQI) values to the cellular network; and inresponse to reporting a CQI value that is within a specified range ofCQI values, adjust radio link monitoring of the wireless communicationdevice.
 20. The non-transitory memory medium of claim 14, wherein theinstructions are executable by the processing element to further causethe wireless communication device to: receive, from the cellularnetwork, a physical channel signaling with a modulation and codingscheme index value that is within a specified range of modulation andcoding scheme index values; and in response to receiving the modulationand coding scheme index value that is within the specified range, adjustradio link monitoring of the wireless communication device.